Micromechanical Resonator

• US 20120229226A1
• Filed: 09/27/2010
• Published: 09/13/2012
• Est. Priority Date: 09/28/2009
• Status: Abandoned Application

• Current Assignee: Teknologian tutkimuskeskus VTT Oy
• Original Assignee: Teknologian tutkimuskeskus VTT Oy
• Inventors: Oja, Aarne, Meltaus, Johanna, Pensala, Tuomas
• Application Number:
  US13/497,805
• Publication Number:
  US 20120229226A1
• Time in Patent Office: Days
• US Class Current: 331/158
• CPC Class Codes: B81B 2201/0271 Resonators; ultrasonic resonators
• CPC Class Codes: B81B 3/0081 Thermal properties
• CPC Class Codes: H03H 2003/027 the resonators or networks being of the microelectro-mechanical [MEMS] type
• CPC Class Codes: H03H 2003/0407 Temperature coefficient
• CPC Class Codes: H03H 2009/02496 Horizontal, i.e. parallel to the substrate plane
• CPC Class Codes: H03H 2009/02503 Breath-like, e.g. Lam? mode, wine-glass mode
• CPC Class Codes: H03H 2009/02511 Vertical, i.e. perpendicular to the substrate plane
• CPC Class Codes: H03H 2009/241 Bulk-mode MEMS resonators
• CPC Class Codes: H03H 2009/2442 Square resonators
• CPC Class Codes: H03H 3/0076 for obtaining desired frequency or temperature coefficients
• CPC Class Codes: H03H 9/02259 Driving or detection means
• CPC Class Codes: H03H 9/02338 Suspension means
• CPC Class Codes: H03H 9/02448 of temperature influence
• CPC Class Codes: H03H 9/2436 Disk resonators
• CPC Class Codes: H03H 9/2452 Free-free beam resonators
• CPC Class Codes: H03H 9/2463 Clamped-clamped beam resonators

Abstract

The invention relates to a micromechanical resonator comprising a substrate (1) of first material (2), a resonator (3) suspended to the supporting structure (1), the resonator (3) being at least partially of the same material (2) as the supporting structure and dimensioned for resonation at a specific frequency f₀, coupling means (5) for initiating, maintaining and coupling the resonation of the resonator (3) to an external circuit (6), and the resonator (3) including second material (4), the thermal properties of which being different from the first material (2). In accordance with the invention the resonator (3) includes the second material (4) located concentrated in specific places of the resonator (3).

Claims

1. Micromechanical resonator comprising:

a supporting structure of first material,

a resonator suspended to the supporting structure, the resonator being at least partially of the same material as the supporting structure and dimensioned for resonation at a specific frequency f₀,

coupling means for initiating, maintaining and coupling the resonation of the resonator to an external circuit,

wherein the resonator includes a second material, the thermal properties of which being different from the first material,

wherein the second material of the resonator is located concentrated in specific places of the resonator, and

wherein the parts of the resonator of the second material are dimensioned laterally larger than 10 μ

m.

2. A resonator in accordance with claim 1, wherein the parts of the resonator of the second material are at least mainly in an area(s) where the resonator has a tension maximum(s) at the specific frequency f₀.

3. A resonator in accordance with claim 1, wherein the parts of the resonator of the second material are at least mainly at the lateral ends of the resonator.

4. A resonator in accordance with claim 1, wherein the first material is silicon and the second material is silicon oxide, Tellurium oxide or glass.

5. A resonator in accordance with claim 1, wherein the resonator is a beam suspended in the middle of the structure to the substrate.

6. A resonator in accordance with claim 1, wherein the resonator is a plate suspended to the substrate from the corners of the plate.

7. A resonator in accordance with claim 1, wherein the parts of the second material are uniform.

8. A resonator in accordance with claim 1, wherein the parts of the second material placed to the stress maximum are only partially filling the first material as trenches or plugs.

9. A resonator in accordance with claim 1, wherein the resonator is a length extensional beam resonator.

10. A resonator in accordance with claim 1, wherein the resonator is a square extensional plate resonator.

11. A resonator in accordance with claim 1, wherein the resonator is a vertical Bulk Acoustic Wave SOI resonator.

12. A resonator in accordance claim 1, wherein the thermal dependence of the sound velocity of the first material is opposite to the second material.